Culturable bacteria from two Portuguese salterns: diversity and bioactive potential
Salterns are extreme environments, where the high salt concentration is the main limitation to microbial growth, along with solar radiation, temperature and pH. These selective pressures might lead to the acquisition of unique genetic adaptations that can manifest in the production of interesting natural products. The present study aimed at obtaining the culturable microbial diversity from two Portuguese salterns located in different geographic regions. A total of 190 isolates were retrieved and identified as belonging to 30 genera distributed among 4 phyla—Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. Specifically, members of the genus Bacillus were the most frequently isolated from both salterns and all actinobacterial isolates belong to the rare members of this group. The molecular screening of NRPS and PKS-I genes allowed the detection of 38 isolates presenting PKS-I, 25 isolates presenting NRPS and 23 isolates presenting both types of biosynthetic genes. Sequencing of randomly selected amplicons revealed similarity with known PKS-I and NRPS genes or non-annotated hypothetical proteins. This study is the first contribution on the culturable bacterial diversity of Portuguese salterns and on their bioactive potential. Ultimately, these findings provide a novel contribution to improve the understanding on the microbial diversity of salterns.
KeywordsSalterns Bacterial isolation Diversity Bioactive potential
The authors thank national funds provided by Fundação para a Ciência e Tecnologia (FCT; Foundation for Science and Technology) at Portugal, and European Regional Development Fund (ERDF) and COMPETE under the Project INNOVMAR—Innovation and Sustainability in the Management and Exploitation of Marine Resources, reference NORTE-01-0145-FEDER-000035, Research Line NOVELMAR. This work was also financed by the Strategic Funding UID/Multi/04423/2019 through national funds provided by FCT and ERDF, in the framework of the programme PT2020. EA thanks FCT for the Ph.D. Grant SFRH/BD/125527/2016. M.F. Carvalho wishes to acknowledge CEEC program supported by FCT (CEECIND/02968/2017), Fundo Social Europeu and Programa Operacional Potencial Humano.
EA wrote the paper, collected samples, performed the experiments. TVD and GF helped on the experiments. MFC and OML collected samples and contributed for paper’s writing.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Human and animal rights
No human neither animals were used on this study. So, no need to report informed consent.
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